An N-terminal region of a Myb-like protein is involved in its intracellular localization and activation of a gibberellin-inducible proteinase gene in germinated rice seeds

Biosci Biotechnol Biochem. 2015;79(5):747-59. doi: 10.1080/09168451.2014.998620. Epub 2015 Jan 6.


The expression of the gene for a proteinase (Rep1) is upregulated by gibberellins. The CAACTC regulatory element (CARE) of the Rep1 promoter is involved in the gibberellin response. We isolated a cDNA for a CARE-binding protein containing a Myb domain in its carboxyl-terminal region and designated the gene Carboxyl-terminal Myb1 (CTMyb1). This gene encodes two polypeptides of two distinctive lengths, CTMyb1L and CTMyb1S, which include or exclude 213 N-terminal amino acid residues, respectively. CTMyb1S transactivated the Rep1 promoter in the presence of OsGAMyb, but not CTMyb1L. We observed an interaction between CTMyb1S and the rice prolamin box-binding factor (RPBF). A bimolecular fluorescence complex analysis detected the CTMyb1S and RPBF complex in the nucleus, but not the CTMyb1L and RPBF complex. The results suggest that the arrangement of the transfactors is involved in gibberellin-inducible expression of Rep1.

Keywords: Myb transcription factor; gibberellin; intracellular localization; rice; seed germination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis Proteins / genetics
  • Base Sequence
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant
  • Germination / genetics*
  • Gibberellins / metabolism*
  • Molecular Sequence Data
  • Oryza / genetics*
  • Peptide Hydrolases / genetics
  • Peptide Hydrolases / metabolism
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Promoter Regions, Genetic
  • Seeds / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism


  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • Gibberellins
  • Myb protein, Arabidopsis
  • PBF protein, plant
  • Plant Proteins
  • Transcription Factors
  • Peptide Hydrolases